Vacuum cleaner

ABSTRACT

A hand-held vacuum cleaner comprising a motor/fan unit configured to generate an airflow having a first direction at an inlet of the motor/fan unit and a first air conducting path arranged downstream of the motor/fan unit. The first air conducting path is configured to direct air to flow in a direction opposite to the first direction. The first air conducting path is arranged radially outside of the motor/fan unit along more than 40% of the length of the motor/fan unit measured in the first direction.

TECHNICAL FIELD

The present disclosure relates to a vacuum cleaner comprising a motor/fan unit configured to generate an airflow in an air conducting path arranged downstream of the motor/fan unit.

BACKGROUND

A vacuum cleaner is an apparatus that uses a motor/fan unit to create a partial vacuum in order to obtain an air flow for sucking up dust and dirt from surfaces, such as floors, carpets, furniture, curtains, and the like. The motor/fan unit usually comprises a centrifugal fan and an electric motor configured to power, i.e. rotate, the centrifugal fan. Several different types of vacuum cleaners exit, including upright/stick type vacuum cleaners, robotic vacuum cleaners, canister vacuum cleaners, and hand-held vacuum cleaners, such as pistol grip hand-held cleaners, and the like.

The fast progress in development of high-power batteries and small electric motors, such as brushless motors, has made battery powered vacuum cleaners able to compete in performance with traditional corded cleaners. Partly as a reason thereof, a current trend for vacuum cleaners is light weighted, small, and easy to handle battery powered vacuum cleaners. However, a slim design together with high power motors puts higher demands on the design of the vacuum cleaner, including solutions for suppressing the noise. In order to keep up air performance with a smaller sized motor/fan unit, many of these motor/fan units have almost doubled the rotational speed in comparison with traditionally large sized motor/fan units. Therefore, these types of motor/fan units can generate a lot of noise.

Noise is problematic because it may disturb and annoy the user as well as people and animals in the vicinity of the vacuum cleaner during use thereof. One efficient way to suppress noise is to use a long air conducting path downstream of the motor/fan unit. However, in vacuum cleaners having a slim design, it is difficult to accommodate such a long air conducting path.

Furthermore, generally, on today's consumer market, it is an advantage if products, such as vacuum cleaners and associated components, systems, and arrangements, have conditions and/or characteristics suitable for being manufactured and assembled in a cost-efficient manner.

SUMMARY

It is an object of the present invention to overcome, or at least alleviate, at least some of the above-mentioned problems and drawbacks.

According to a first aspect of the invention, the object is achieved by a hand-held vacuum cleaner comprising a motor/fan unit configured to generate an airflow having a first direction at an inlet of the motor/fan unit and a first air conducting path arranged downstream of the motor/fan unit. The first air conducting path is configured to direct air to flow in a direction opposite to the first direction. The first air conducting path is arranged radially outside of the motor/fan unit along more than 40% of the length of the motor/fan unit measured in the first direction.

Thereby, a hand-held vacuum cleaner is provided allowing for a long air conducting path downstream of the motor/fan unit while conditions are provided for a slim design of the vacuum cleaner. This because the hand-held vacuum cleaner comprises the first air conducting path arranged radially outside of the motor/fan unit along more than 40% of the length of the motor/fan unit which is configured to direct air to flow in a direction opposite to the first direction. Accordingly, due to these features, the available space inside the hand-held vacuum cleaner is utilized in an efficient manner thereby allowing for a long air conducting path downstream of the motor/fan unit. Since a long air conducting path is allowed for downstream of the motor/fan unit, conditions are provided for a high level of noise attenuation.

Furthermore, since the first air conducting path is configured to direct air to flow in a direction opposite to the first direction, conditions are provided for a high level of noise attenuation because noise may be deflected and reflected by surfaces of the first air conducting path in an efficient manner so as to attenuate noise.

Moreover, because the first air conducting path is arranged radially outside of the motor/fan unit along more than 40% of the length of the motor/fan unit, the first air conducting path may per se provide attenuation of noise generated by the motor/fan unit.

Furthermore, because the first air conducting path is arranged radially outside of the motor/fan unit along more than 40% of the length of the motor/fan unit, the first air conducting path may provide some cooling of the motor/fan unit. Thereby, conditions are provided for operating the motor/fan unit at higher power levels without overheating the motor/fan unit.

Accordingly, a hand-held vacuum cleaner is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the first air conducting path is arranged radially outside of the motor/fan unit along more than 80% of the length of the motor/fan unit. Thereby, a hand-held vacuum cleaner is provided allowing for an even longer air conducting path downstream of the motor/fan unit while conditions are provided for a slim design of the hand-held vacuum cleaner. Since an even longer air conducting path is allowed for downstream of the motor/fan unit, conditions are provided for an even higher level of noise attenuation.

Moreover, because the first air conducting path is arranged radially outside of the motor/fan unit along more than 80% of the length of the motor/fan unit, the first air conducting path per se may provide a greater attenuation of noise generated by the motor/fan unit.

Furthermore, because the first air conducting path is arranged radially outside of the motor/fan unit along more than 80% of the length of the motor/fan unit, the first air conducting path may provide greater cooling efficiency of the motor/fan unit. Thereby, conditions are provided for operating the motor/fan unit at even higher power levels without overheating the motor/fan unit.

Optionally, the first air conducting path is arranged radially outside of the motor/fan unit along the entire length of the motor/fan unit. Thereby, a hand-held vacuum cleaner is provided allowing for an even longer air conducting path downstream of the motor/fan unit while conditions are provided for a slim design of the hand-held vacuum cleaner. Since an even longer air conducting path is allowed for downstream of the motor/fan unit, conditions are provided for an even higher level of noise attenuation.

Moreover, because the first air conducting path is arranged radially outside of the motor/fan unit along the entire length of the motor/fan unit, the first air conducting path per se may provide a greater attenuation of noise generated by the motor/fan unit.

Furthermore, because the first air conducting path is arranged radially outside of the motor/fan unit along the entire length of the motor/fan unit, the first air conducting path may provide greater cooling efficiency of the motor/fan unit. Thereby, conditions are provided for operating the motor/fan unit at even higher power levels without overheating the motor/fan unit.

Optionally, the first air conducting path at least partially encloses the motor/fan unit. Since the first air conducting path at least partially encloses the motor/fan unit, the first air conducting path per se may provide a greater attenuation of noise generated by the motor/fan unit. Moreover, a large cross sectional area of the first air conducting path is allowed for while providing conditions for a slim and compact hand-held vacuum cleaner. Furthermore, the first air conducting path may provide greater cooling efficiency of the motor/fan unit. Thereby, conditions are provided for operating the motor/fan unit at even higher power levels without overheating the motor/fan unit.

Optionally, the first air conducting path encloses more than 50% of the circumference of the motor/fan unit. Thereby, a great attenuation of noise generated by the motor/fan unit can be ensured. Moreover, the first air conducting path may provide greater cooling efficiency of the motor/fan unit. Thereby, conditions are provided for operating the motor/fan unit at even higher power levels without overheating the motor/fan unit.

Optionally, the first air conducting path comprises an air diverting portion configured to change the airflow direction approximately 180 degrees, and wherein the air diverting portion is arranged directly downstream of the motor/fan unit. Thereby, conditions are provided for a slim and compact hand-held vacuum cleaner while allowing for a long air conducting path downstream of the motor/fan unit.

Optionally, the hand-held vacuum cleaner comprises a handle assembly and a second air conducting path arranged downstream of the first air conducting path, and wherein the second air conducting path extends through a portion of the handle assembly. Thereby, conditions are provided for a long air conducting path downstream of the motor/fan unit so as to attenuate nose in an efficient manner while allowing for a slim and compact hand-held vacuum cleaner.

Optionally, the handle assembly comprises an elongated handle unit configured to be gripped by a user during operation of the hand-held vacuum cleaner and a second elongated unit arranged at a distance from the elongated handle unit, and wherein the second air conducting path extends through at least a portion of the second elongated unit. Thereby, conditions are provided for a long air conducting path downstream of the motor/fan unit so as to attenuate nose in an efficient manner while allowing for a slim and compact hand-held vacuum cleaner.

Moreover, a hand-held vacuum cleaner is provided in which the elongated handle unit is not significantly heated during operation of the hand-held vacuum cleaner. Thereby, a more user friendly hand-held vacuum cleaner is provided being more comfortable to use.

Optionally, the hand-held vacuum cleaner comprises an air outlet arranged on the second elongated unit. Thereby, conditions are provided for a long air conducting path downstream of the motor/fan unit so as to attenuate noise in an efficient manner while allowing for a slim and compact hand-held vacuum cleaner. Moreover, a hand-held vacuum cleaner is provided in which the air flowing through the air outlet can be directed in directions pointing away from a user of the hand-held vacuum cleaner in an efficient manner. Thereby, a more user friendly hand-held vacuum cleaner is provided being more comfortable to use.

Optionally, the hand-held vacuum cleaner comprises a battery assembly configured to supply electricity to the motor/fan unit. Thereby, a battery powered hand-held vacuum cleaner is provided having conditions for slim and compact design and having conditions for a high level of noise attenuation. Moreover, a user friendly hand-held vacuum cleaner is provided being more comfortable to use.

Optionally, the battery assembly is supported relative to a main body of the hand-held vacuum cleaner via the elongated handle unit and the second elongated unit. Thereby, a rigid and durable hand-held vacuum cleaner can be provided in which the second elongated unit can be utilized for accommodating at least a portion of the second air conducting path. As a further result thereof, conditions are provided for a long air conducting path downstream of the motor/fan unit so as to provide an efficient noise attenuation.

Optionally, the hand-held vacuum cleaner comprises an air outlet comprising at least a portion being arranged in front of the motor/fan unit seen along the first direction. Thereby, conditions are provided for a long air conducting path downstream of the motor/fan unit so as to attenuate nose in an efficient manner while allowing for a slim and compact hand-held vacuum cleaner. Moreover, a hand-held vacuum cleaner is provided in which the air flowing through the air outlet can be directed in directions pointing away from a user of the hand-held vacuum cleaner in an efficient manner. Thereby, a more user friendly hand-held vacuum cleaner is provided being more comfortable to use.

Optionally, the hand-held vacuum cleaner comprises an air outlet being a perforated section of a body component of the hand-held vacuum cleaner. Thereby, conditions are provided for an even higher level of noise attenuation. Moreover, an air outlet is provided having conditions for generating lower flow velocities through the air outlet as compared to a traditional air outlet. As a further result, a more user friendly hand-held vacuum cleaner can be provided being more comfortable to use.

Optionally, the perforated section comprises a number of small-sized through-holes through the body component, and wherein a total cross sectional area of the number of small-sized through-holes is equal to, or greater than, the cross sectional area of the first air conducting path. Thereby, an air outlet is provided having conditions for generating lower flow velocities through the air outlet while providing a low flow resistance through the air outlet. Thereby, a high operational efficiency of the hand-held vacuum cleaner can be ensured.

Optionally, the hand-held vacuum cleaner comprises power electronics configured to control operation of the motor/fan unit, and wherein the hand-held vacuum cleaner comprises an air channel configured to direct a partial flow of air past the power electronics to a secondary air outlet of the hand-held vacuum cleaner to cool the power electronics. Thereby, cooling of the power electronics is obtained in a simple and cost-efficient manner.

Optionally, the hand-held vacuum cleaner comprises a main body which accommodates at least the motor/fan unit and the first air conducting path, and wherein the air channel is arranged on the main body. Thereby, cooling of the power electronics can be obtained in a simple and cost-efficient manner while conditions are provided for a slim and compact design of the hand-held vacuum cleaner.

Optionally, the air channel is arranged behind the motor/fan unit seen along the first direction. Thereby, cooling of the power electronics can be obtained in a simple and cost-efficient manner while conditions are provided for a slim and compact design of the hand-held vacuum cleaner.

Optionally, the secondary air outlet is arranged on the main body at a location behind the motor/fan unit seen along the first direction. Thereby, cooling of the power electronics can be obtained in a simple and cost-efficient manner while conditions are provided for a slim and compact design of the hand-held vacuum cleaner.

Optionally, the hand-held vacuum cleaner comprises a second air conducting path arranged downstream of the first air conducting path, wherein walls of at least one of the first and second air conducting paths are covered by a noise attenuating material. Thereby, a hand-held vacuum cleaner is provided having conditions for an even greater attenuation of noise.

Optionally, the hand-held vacuum cleaner comprises a perforated cylindrical body arranged around the motor/fan unit, and wherein the first air conducting path extends at least partially through holes of the perforated body. Thereby, conditions are provided for an even greater noise attenuation while ensuring a slim and compact design of the hand-held vacuum cleaner. This because noise can be deflected and reflected in a more efficient manner due to the perforated cylindrical body.

Optionally, the hand-held vacuum cleaner is a small-sized hand-held vacuum cleaner. Thereby, a small-sized hand-held vacuum cleaner is provided allowing for a long air conducting path downstream of the motor/fan unit while conditions are provided for a slim design of the vacuum cleaner. This because the small-sized hand-held vacuum cleaner comprises the first air conducting path arranged radially outside of the motor/fan unit along a significant portion of the motor/fan unit which is configured to direct air to flow in a direction opposite to the first direction. Accordingly, due to these features, the available space inside the small-sized hand-held vacuum cleaner is utilized in an efficient manner thereby allowing for a long air conducting path downstream of the motor/fan unit. As a result, conditions are provided for a high level of noise attenuation in the small-sized hand-held vacuum cleaner.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the invention, including its particular features and advantages, will be readily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which:

FIG. 1 illustrates a cross section of a hand-held vacuum cleaner according to some embodiments,

FIG. 2 illustrates an enlarged view of the motor/fan unit of the hand-held vacuum cleaner illustrated in FIG. 1 , and

FIG. 3 illustrates a cross section of a hand-held vacuum cleaner according to some further embodiments.

DETAILED DESCRIPTION

Aspects of the present invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

FIG. 1 illustrates a cross section of a hand-held vacuum cleaner 1 according to some embodiments. According to the illustrated embodiments, the vacuum cleaner 1 is a so called pistol grip handheld vacuum cleaner which can be operated using one hand. The feature “hand-held”, as used herein, means that the vacuum cleaner 1 is configured to be operated and supported using one or two hands of a user. For reasons of brevity and clarity, the hand-held vacuum cleaner 1 is in some places herein referred to as “the vacuum cleaner 1”.

The vacuum cleaner 1 comprises a suction inlet 3 and an air outlet 5. Moreover, the vacuum cleaner 1 comprises a motor/fan unit 7 configured to generate an airflow from the suction inlet 3 to the air outlet 5. During operation of the motor/fan unit 7, a partial vacuum is generated at the suction inlet 3 which can be used to collect dust. The vacuum cleaner 1 comprises a dust separator 6 between the suction inlet 3 and the motor/fan unit 7. According to the illustrated embodiments, the dust separator 6 comprises a cyclone separator. As an alternative, or in addition, the vacuum cleaner 1 may comprise another type of dust separator, such as a dust bag, or the like. Moreover, according to the illustrated embodiments, the vacuum cleaner 1 comprises a filter 8 arranged between the dust separator 6 and the motor/fan unit 7. The filter 8 may comprise a foam material and may be configured to further separate fine particles from the air flowing towards an inlet 7′ of the motor/fan unit 7. As is further explained herein, the motor/fan unit 7 is configured to generate an airflow having a first direction d1 at the inlet 7′ of the motor/fan unit 7.

FIG. 2 illustrates an enlarged view of the motor/fan unit 7 of the vacuum cleaner 1 illustrated in FIG. 1 . The motor/fan unit 7 comprises a fan 14 and a motor 16. The motor 16 is configured to rotate the fan 14 around a rotation axis Ax via a shaft 18. The shaft 18 is schematically indicated in dashed lines in FIG. 2 . The motor 16 is an electric motor. According to some embodiments, the motor 16 may be a brushless electric motor. According to further embodiments, the motor 16 may be a brushed motor. The motor 16 comprises a rotor 23 connected to the fan 14 via the shaft 18. According to the illustrated embodiments, the rotor 23, the shaft 18, and the fan 14 are concentrically arranged meaning that they all rotate around the rotation axis Ax during operation of the motor/fan unit 7. The fan 14 may be a radial fan comprising a number of guide wanes configured to generate an airflow by forcing air in radial directions of the fan 14 during rotation of the fan 14. According to the illustrated embodiments, the motor/fan unit 7 comprises a diffuser 24. The diffusor 24 may comprise a number of stator blades configured to straighten out the airflow downstream of the fan 14 and thereby increase the operational efficiency of the motor/fan unit 7.

As indicated above, the motor/fan unit 7 is configured to generate an airflow having a first direction d1 at the inlet 7′ of the motor/fan unit 7. According to the illustrated embodiments, the first direction d1 is parallel to the rotation axis Ax of the fan 14, and consequently also parallel to the rotation axis Ax of the shaft 18 and the rotation axis Ax of the rotor 23 of the motor 16. The first direction d1 may also be referred to as an inlet direction d1 of air flowing into the motor/fan unit 7. The first direction d1 may correspond to an average air flow direction through the motor/fan unit 7 and may also be referred to as an operational air flow direction of the motor/fan unit 7.

In FIG. 2 , the airflow through the motor/fan unit 7 is schematically indicated in dotted lines. During operation of the motor/fan unit 7, the air is flowing into the fan 14 via the inlet 7′ of the motor/fan unit 7. The fan 14 forces the air in radial directions of the fan 14, i.e. in directions perpendicular to the first direction d1. The air is then guided through the motor 16 via the diffusor 24. The air thus flows through the motor 16 and thereby cools the motor 16. The air may flow through the rotor 23 of the motor 16 as well through a stator 26 of the motor 16. According to the illustrated embodiments, the motor/fan unit 7 comprises an outlet 7″ configured to direct air to flow out of the outlet 7″ in directions substantially coinciding with the first direction d1. According to further embodiments, the motor/fan unit 7 may comprise one or more outlets configured to direct air to flow out of the outlet in directions differing from the first direction d1, such that in directions substantially perpendicular to the first direction d1, i.e. in substantially radial directions of the motor/fan unit 7. Such one or more outlets may each be referred to as a radial outlet.

Below, simultaneous reference is made to FIG. 1 and FIG. 2 , if not indicated otherwise. The vacuum cleaner 1 comprises a first air conducting path 11. The first air conducting path 11 is arranged downstream of the motor/fan unit 7. The vacuum cleaner 1 comprises a main body 9 which accommodates the motor/fan unit 7 and the first air conducting path 11. As can be seen in FIG. 1 and in FIG. 2 , the first air conducting path 11 is configured to direct air to flow in a direction d2 opposite to the first direction d1. That is, as can be seen in FIG. 1 and in FIG. 2 , the first air conducting path 11 comprises an air diverting portion 11′ configured to change the airflow direction approximately 180 degrees, i.e. change the direction of flow from the first direction d1 to the direction d2 opposite to the first direction d1. The direction d2 opposite to the first direction d1 may also be referred to as a second direction d2. According to the illustrated embodiments, the air diverting portion 11′ is arranged directly downstream of the motor/fan unit 7, i.e. directly downstream of the outlet 7″ of the motor/fan unit 7. According to further embodiment, such as embodiments in which the motor/fan unit 7 comprises one or more radial outlets, as referred to above, the motor/fan unit 7 may comprise at least part of the air diverting portion 11′.

Moreover, as is clearly seen in FIG. 1 and FIG. 2 , and as is indicated in FIG. 1 , according to the illustrated embodiments, the first air conducting path 11 is arranged radially outside of the motor/fan unit 7 along the entire length L of the motor/fan unit 7 measured along the first direction d1. In other words, according to the illustrated embodiments, the first air conducting path 11 extends radially outside of the motor/fan unit 7 a distance corresponding to the entire length L of the motor/fan unit 7 measured in the first direction d1. According to further embodiments, the first air conducting path 11 may be arranged radially outside of the motor/fan unit 7 along more than 40%, or more than 80%, of the length L of the motor/fan unit 7 measured in the first direction d1.

Thereby, a vacuum cleaner 1 is provided allowing for a long air conducting path 11, 12 downstream of the motor/fan unit 7 while conditions are provided for a slim design of the vacuum cleaner 1. Since a long air conducting path 11, 12 is allowed for downstream of the motor/fan unit 7, conditions are provided for an efficient attenuation of noise, as is further explained herein.

According to the embodiments illustrated in FIG. 1 and FIG. 2 , the first air conducting path 11 encloses almost the entire circumference of the motor/fan unit 7. According to further embodiments, the first air conducting path 11 may enclose more than 20%, or more than 50%, of the circumference of the motor/fan unit 7. Thereby, a great attenuation can be ensured of noise generated by the motor/fan unit 7. Moreover, the first air conducting path 11 may provide cooling of the motor/fan unit 7. In addition, a large cross sectional area of the first air conducting path 11 is allowed for while providing conditions for a slim and compact vacuum cleaner 1.

As can be seen in FIG. 1 , according to the illustrated embodiments, the vacuum cleaner 1 comprises a handle assembly 20. The handle assembly 20 comprises an elongated handle unit 21. The elongated handle unit 21 is configured to be gripped by a user in an intended grip direction during operation of the vacuum cleaner 1. According to the illustrated embodiments, the intended grip direction of the elongated handle unit 21 is substantially opposite to the first direction d1. The handle assembly 20 further comprises a second elongated unit 22 arranged at a distance from the elongated handle unit 21. According to the illustrated embodiments, the second elongated unit 22 is substantially parallel to the elongated handle unit 21. The handle assembly 20 is arranged such that the second elongated unit 22 faces fingers of a user when the user grips the elongated handle unit 21 in the intended grip direction.

According to the illustrated embodiments, the vacuum cleaner 1 comprises a battery assembly 25. The battery assembly 25 is configured to supply electricity to the motor/fan unit 7. The battery assembly 25 may comprise a number of rechargeable battery cells, such as a number of lithium ion battery cells. As can be seen in FIG. 1 , according to the illustrated embodiments, the battery assembly 25 is supported relative to a main body 9 of the vacuum cleaner 1 via the elongated handle unit 21 and via the second elongated unit 22. The elongated handle unit 21 may therefore also be referred to as a first elongated handle/support unit 21 and the second elongated unit 22 also be referred to as a second support unit 22, or a second handle/support unit 22.

According to the illustrated embodiments, the vacuum cleaner 1 comprises a second air conducting path 12 arranged downstream of the first air conducting path 11. The second air conducting path 12 extends through at least a portion of the second elongated unit 22 and thus through a portion of the handle assembly 20. In this manner, a long air conducting path 11, 12 is allowed for downstream of the motor/fan unit 7 while conditions are provided for a vacuum cleaner 1 having a compact and slim design. Furthermore, due to these features, an air conducting path 11, 12 is provided downstream of the motor/fan unit 7 comprising several bends and turns. As a result thereof, the noise is attenuated in a more efficient manner because the noise can be deflected and reflected against walls of the air conducting path 11, 12. Moreover, since the second elongated unit 22 is utilized for accommodating a portion of the second air conducting path 12, instead of the elongated handle unit 21, the palm and fingers of a user are not heated during operation of the vacuum cleaner 1. Thereby, a more user-friendly vacuum cleaner 1 is provided being more comfortable to use.

Moreover, as seen in FIG. 1 , according to the illustrated embodiments, the air outlet 5 of the vacuum cleaner 1 is arranged on the second elongated unit 22. In more detail, according to the illustrated embodiments, the air outlet 5 is arranged on a side of the second elongated unit 22 which faces away from the elongated handle unit 21. Moreover, the air outlet 5 comprises at least a portion 5′ being arranged in front of the motor/fan unit 7 seen along the first direction d1. Also for these reasons, a more user-friendly vacuum cleaner 1 is provided being more comfortable to use. This is because the air flowing out from the air outlet 5 will flow in directions away from the elongated handle unit 21 and thereby also in directions away from the hand of a user during operation of the vacuum cleaner 1. Moreover, due to these features, conditions are provided for a long air conducting path downstream of the motor/fan unit 7 so as to attenuate nose in an efficient manner while allowing for a slim and compact design of the vacuum cleaner 1.

Moreover, as seen in FIG. 1 , according to the illustrated embodiments, the air outlet 5 of the vacuum cleaner 1 is a perforated section 5″ of a body component 22 of the vacuum cleaner 1, namely a perforated section 5″ of the second elongated unit 22. Also for this reason, a more user-friendly vacuum cleaner 1 is provided being more comfortable to use. This is because the air flowing out from the air outlet 5 will have a low flow velocity.

As is indicated in FIG. 1 , according to the illustrated embodiments, the perforated section 5″ comprises a number of small-sized through-holes 15 through the second elongated unit 22. A total cross sectional area of the number of small-sized through-holes 15 may be equal to, or greater than, the cross sectional area of the first air conducting path 11, and/or equal to, or greater than, the cross sectional area of the second air conducting path 12. In this manner, a low flow resistance through the air outlet 5 is obtained which provides conditions for a high operational efficiency of the vacuum cleaner 1 while conditions are provided for a high level of noise attenuation.

According to some embodiments, walls 51, 52 of at least one of the first and second air conducting paths 11, 12 may be covered by a noise attenuating material. In this manner, the noise can be attenuated with an even higher efficiency. The noise attenuating material may comprise a soft foam material and/or a soft or harder sponge material. According to some embodiments, walls 51, 52 of the first and second air conducting paths 11, 12 may be covered by a combination of a soft foam material and a harder sponge material. In this manner, noise at different frequencies can be attenuated in an efficient manner.

The vacuum cleaner 1 comprises power electronics 27 configured to control operation of the motor/fan unit 7. According to the illustrated embodiments, the vacuum cleaner 1 comprises an air channel 29 and a secondary air outlet 35. According to the illustrated embodiments, the air channel 29 is fluidly connected to the air diverting portion 11′ of the first air conducting path 11. The air channel 29 is configured to direct a partial flow of air past the power electronics 27 to the secondary air outlet 35 of the vacuum cleaner 1 to cool the power electronics 27.

As can be seen in FIG. 1 , according to the illustrated embodiments, the air channel 29 is arranged on the main body 9 at a location behind the motor/fan unit 7 seen along the first direction d1. Likewise, the secondary air outlet 35 is arranged on the main body 9 at a location behind the motor/fan unit 7 seen along the first direction d1. In FIG. 1 , the vacuum cleaner 1 is illustrated as comprising one air channel 29 connected to one secondary air outlet 35. However, the vacuum cleaner 1 may comprise a number of air channels 29 each connected to a respective secondary outlet 35. Due to these features, an efficient cooling of the power electronics 27 is provided in a simple and cost-efficient manner while conditions are provided for a slim and compact design of the vacuum cleaner 1.

FIG. 3 illustrates a cross section of a vacuum cleaner 1 according to some further embodiments. The vacuum cleaner 1 according to the embodiments illustrated in FIG. 3 may comprise the same features, functions, and advantages as the vacuum cleaner 1 explained with reference to FIG. 1 , with some differences explained below. Like reference numbers refer to like elements throughout.

According to the embodiments illustrated in FIG. 3 , the vacuum cleaner 1 comprises a perforated cylindrical body 17. The perforated cylindrical body 17 is arranged concentrically arranged around the motor/fan unit 7. As is indicated in FIG. 3 , the first air conducting path 11 extends at least partially through holes 19 of the perforated body 17. That is, the holes 19 of the perforated body 17 are through-holes through which air from the motor/fan unit 7 can flow. As can be seen in FIG. 3 , the holes 19 are distributed across the surface of the perforated cylindrical body 17 and also distributed across the length L of the perforated cylindrical body 17. This means that air flowing through holes 19 positioned closer to the inlet 7′ of the motor/fan unit 7 may flow a shorter distance through the air conducting path of the vacuum cleaner 1 than air flowing through a hole 19 positioned a further distance from the inlet 7′ of the motor/fan unit 7. However, also in these embodiments, the first air conducting path 11 is arranged radially outside of the motor/fan unit 7 along the entire length L of the motor/fan unit 7 measured in the first direction d1.

In other words, according to the illustrated embodiments, the first air conducting path 11 extends radially outside of the motor/fan unit 7 a distance corresponding to the entire length L of the motor/fan unit 7 measured in the first direction d1. This is because the first air conducting path 11 of the vacuum cleaner 1 according the illustrated embodiments comprises at least a portion extending along the entire length L of the motor/fan unit 7 measured in the first direction d1, as is indicated in FIG. 3 . However, according to further embodiments of the vacuum cleaner 1 illustrated in FIG. 3 , the first air conducting path 11 is may be arranged radially outside of the motor/fan unit 7 along more than 40%, or more than 80%, of the length L of the motor/fan unit 7 measured in the first direction d1.

Due to the perforated cylindrical body 17 arranged around the motor/fan unit 7, conditions are provided for an even higher level of noise attenuation while ensuring a slim and compact design of the vacuum cleaner 1. This is because noise can be deflected and reflected in a more efficient manner due to the perforated cylindrical body 17.

The wording “downstream” as used herein, describes the location/position of the component referred to relative an intended flow direction through the air conducting path of the vacuum cleaner 1, wherein the air conducting path of the vacuum cleaner 1 extends from the suction inlet 3 of the vacuum cleaner 1 to the air outlet 5 of the vacuum cleaner 1. As specified herein, the motor/fan unit 7 is configured to generate an airflow from the suction inlet 3 to the air outlet 5 during operation of the motor/fan unit 7. Accordingly, the feature that the first air conducting path 11 is arranged downstream of the motor/fan unit 7 means that the first air conducting path 11 is arranged downstream of the motor/fan unit 7 relative to the flow direction through the motor/fan unit 7 and through the first air conducting path 11. In other words, the feature that the first air conducting path 11 is arranged downstream of the motor/fan unit 7 means that the first air conducting path 11 is arranged after the motor/fan unit 7 relative to the flow direction through the motor/fan unit 7 and through the first air conducting path 11. Thus, air pumped through the air conducting path of the vacuum cleaner 1 will first flow through motor/fan unit 7 and then through the first air conducting path 11.

The same applies to the positions/locations of the first and second air conducting paths 11, 12. That is, the feature that the second air conducting path 12 is arranged downstream of the first air conducting path 11 means that the second air conducting path 12 is arranged downstream of the first air conducting path 11 relative to the flow directions through the first and second air conducting paths 11, 12. In other words, the feature that the second air conducting path 12 is arranged downstream of the first air conducting path 11 means that the second air conducting path 12 is arranged after the first air conducting path 11 relative to the flow directions through the first and second air conducting paths 11, 12. Thus, air pumped through the air conducting path 11, 12 of the vacuum cleaner 1 will first flow through the first air conducting path 11 and then through the second air conducting path 12.

It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, without departing from the scope of the present invention, as defined by the appended claims.

As used herein, the term “comprising” or “comprises” is open-ended, and includes one or more stated features, elements, steps, components, or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions, or groups thereof. 

1. A hand-held vacuum cleaner comprising: a motor/fan unit configured to generate an airflow having a first direction at an inlet of the motor/fan unit; and a first air conducting path arranged downstream of the motor/fan unit; wherein the first air conducting path is configured to direct air to flow in a direction opposite to the first direction, and the first air conducting path is arranged radially outside of the motor/fan unit along more than 40% of a length of the motor/fan unit measured in the first direction.
 2. The hand-held vacuum cleaner according to claim 1, wherein the first air conducting path is arranged radially outside of the motor/fan unit along more than 80% of the length of the motor/fan unit.
 3. The hand-held vacuum cleaner according to claim 1, wherein the first air conducting path is arranged radially outside of the motor/fan unit along the entire length of the motor/fan unit.
 4. The hand-held vacuum cleaner according to claim 1, wherein the first air conducting path at least partially encloses the motor/fan unit.
 5. The hand-held vacuum cleaner according to claim 4, wherein the first air conducting path encloses more than 50% of a circumference of the motor/fan unit.
 6. The hand-held vacuum cleaner according to claim 1, wherein the first air conducting path comprises an air diverting portion configured to change the airflow direction 180 degrees, and wherein the air diverting portion is arranged directly downstream of the motor/fan unit.
 7. The hand-held vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises a handle assembly and a second air conducting path arranged downstream of the first air conducting path, and wherein the second air conducting path extends through a portion of the handle assembly.
 8. The hand-held vacuum cleaner according to claim 7, wherein the handle assembly comprises an elongated handle unit configured to be gripped by a user during operation of the vacuum cleaner and a second elongated unit arranged at a distance from the elongated handle unit, and wherein the second air conducting path extends through at least a portion of the second elongated unit.
 9. The hand-held vacuum cleaner according to claim 8, wherein the vacuum cleaner comprises an air outlet arranged on the second elongated unit.
 10. The hand-held vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises a battery assembly configured to supply electricity to the motor/fan unit.
 11. The hand-held vacuum cleaner according to claim 8, wherein the vacuum cleaner comprises a battery assembly configured to supply electricity to the motor/fan unit, and wherein the battery assembly is supported relative to a main body of the vacuum cleaner via the elongated handle unit and the second elongated unit.
 12. The hand-held vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises an air outlet comprising at least a portion being arranged in front of the motor/fan unit seen along the first directions.
 13. The hand-held vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises an air outlet comprising a perforated section of a body component of the vacuum cleaner.
 14. The hand-held vacuum cleaner according to claim 13, wherein the perforated section comprises a number of small-sized through-holes through the body component, and wherein a total cross sectional area of the number of small-sized through-holes is equal to, or greater than, a cross sectional area of the first air conducting path.
 15. The hand-held vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises power electronics configured to control operation of the motor/fan unit, and wherein the vacuum cleaner comprises an air channel configured to direct a partial flow of air past the power electronics to a secondary air outlet of the vacuum cleaner to cool the power electronics.
 16. The hand-held vacuum cleaner according to claim 15, wherein the vacuum cleaner comprises a main body which accommodates at least the motor/fan unit and the first air conducting path, and wherein the air channel is arranged on the main body.
 17. The hand-held vacuum cleaner according to claim 16, wherein the air channel is arranged behind the motor/fan unit seen along the first direction.
 18. The hand-held vacuum cleaner according to claim 16, wherein the secondary air outlet is arranged on the main body at a location behind the motor/fan unit seen along the first direction.
 19. The hand-held vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises a second air conducting path arranged downstream of the first air conducting path, and wherein walls of at least one of the first and second air conducting paths are covered by a noise attenuating material.
 20. The hand-held vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises a perforated cylindrical body arranged around the motor/fan unit, and wherein the first air conducting path extends at least partially through holes of the perforated cylindrical body. 